Control valve



Feb. l2, 1935. R, v. PRoc'roR ET Ax. 1,991,227

CNTROL VALVE Filed July 30, 1932 5 Sheets-Sheet l IIIII Il |I|l\\ IIIKIINI .l

Z I VENTO? Feb. l2, 1935. R, V, PROCTQR ET AL `1,991,227

CONTROL VALVE Filed July so, 1932 5 sheets-sheet 2 Feb. 12, 1935.` R. v.PRocToR ET AL y CONTROL VALVE Filed July 50, .1932 5 ySheets--Sheet 5 Mlll.-

Il n@ Feb. l2, 1935,` R. v. PRocToR Er AL CONTROL VALVE Filed July 30,1932 5y Sheets-Sheet 4 INVENTORS Fb. 12, 1935. R. v. PRocToR YETAL1,991,227

CONTROL VALVE omTEosTATE-:s

Patented Feb. i2, `1935` PATENT. OFFICE i 1,991,227 4CONTROL VALVERobert. v. Proctorfana William T. Stephens,

Youngstown, Ohio, assignors to The Commer-v cialShearing & StampingCompany, Youngstown; Ohio,` a corporation of Ohio Y Application, Jury3o, 1932, serial No. 626,414`

14 claims." (cien-46) Our inventionrelatesV `to valves for controllingthe supply of fluid to fluid-operated devices such as hoisting jacks andthe like.` l

It has been proposed heretofore to provide an automatic cut-offforplug'valves such that when a fluid-operated device'reached the limitof its movement, the increasingvpressure in the supply line would resetthe `valve so that the fluid would be by-passed and no longer deliveredto the fluidoperated device. In allsuch valves-of which we are aware;there is an actual vmovement of "the valve in the resetting operationaccompanied by a `corresponding movement 'of the valve handle or othermanual actuating means." Such movement ofthe valve actuating meansisiobjection`` able, especially if the means Vis a lever, because of thedanger` of injury to the operators` hand on sudden resetting movement ofthe valve. In mulresponse to the'building up of `pressure inthe supplyline. so as to relieve such pressure and permit continued circulation.offluid through the valve under little orno pressure. According to ourinvention.` the by-passing operation does not require Vany movement ofthe valve proper. This means that the actuating mechanism for the valve,whether a lever orhand wheel or the like, is not` operated by theresetting of the valve and there is no danger of injury to the operatorshand. When the invention is applied to multiple valves, furthermore, theexpenditure of energy required for operation of the by-passing mechanismis con-` stant and independent tof vthe number of valves which have beenoperated.` The-time required for by-passing is thus constant and may bemade quitefsmall. Sincev the-invention doesnot require `actual movementof the main valves, the

`friction which would` have to be overcome in so doing :does not limitthe `nurnberof valves which can be `controlled by a` single `by-passingmechanismQ, l M

In accordance with our invention, we employ a control valve `of thetapered plug type. A checkl valve is incorporated in the main valvecasting so as to be traversed by the fluid before it reaches the .plugvalve. A by-passing valve which' is normally maintained closed byfalightspring and is preferably ofthe sleeveor piston type, controls apassage from the valve inlet to the valve outlet which extends around orin parallel with the main passage through the valve which is controlledby` the tapered plug. The by-passing valve is controlled by a reliefvalve responsive to the pres` sure in the supply line.` When theby-passing` valve hasbeen operated bylthe opening of the relief valve,it is held in operated position until `the mainvalve is manuallyrestored, whereupon the lay-passing valve is automatically reclosed andconditions'restored to normal:` The check valve holds the fluid-operateddevice in extendedv position after operation of the relief and bypassingvalves.

A multiple valve incorporating our invention comprises inlet and outletports connecting with high pressure and low pressure passages adaptedto` supply a plurality of valve plugsinr parallel. These plugs controlthe application of fluid pressure to a plurality of fluid-operateddevices. `A by-passing passage also branches from the high pressurepassage to thelow pressure passage and each of the individual valveplugs has a portion for controlling the by-'passing pass`age, -which isopen when all the valves are in normal position passing,y valve such asthat previously mentioned, i

in response to the operation of a relief valve. The by-passing valve isheld in operative `position until the pressure withinthefluid-operated-device is removed from the highpressure passage by themanual resettingof allA the main valves which. have been operated.Ableeder valve then per-` mits the by-passing valve to reset itself. f

Another feature of the multiple valve embodying our invention. is thatsimilar plugs may Vbe employed to control single acting or double actinghoists merely by reversing the plugs intheir bores. N

For-a complete `understanding of the invention, reference is made to`the accompanying drawings illustrating a present preferred embodif mentofthe invention, including a `single valve and a multiple valve. t In,`the drawings: f Figure l is a'partial side elevation showing oneapplication ofthe invention, namely, the control of the hoisting jackfor a tilting vehicle body; Figure 2 is a side elevation of the-singlevalve; Figure 3 is a sectional view taken along the line III-III ofFigure 2;

Figure 3a is a vpartial section along the line IIIa--IIIa of Figure 3;

Figure 4 is a sectional view taken along the line`IV--IV of Figure 3;

Figure 5 is a bottom view of the single Valve with parts removed;

Figure 6 is a side elevation, partly in section,

V of the multiple valve;

vention is shown as incorporated in a single valve4r 10. As an exampleof the uses to whichthe valve may be put, there is shownin part a'motortruck chassis 11 having cross members 12 supported thereon. 'Ihe crossmembers, only one o1' which is shown, are provided with pin and sockethinges 13 for tiltably supporting a dumping body 14. A telescoping jack15 for hoisting the. body 14 is universally trunnioned to the body at 16and to` the chassis at 17. The structure so far described, except thevalve 10, is more fully disclosed and claimed in the co-pendingapplication of Camille P. Galanot, Serial No. 257,707, now Patent No.1,909,341, dated May 16, 1933. t

In addition to the valve and the hoisting jack'15, the hydraulic systemof whichthey are a part includes a storage tank 18, a pump 19 and meansfor driving the pump,'such as a power take-off 20, mounted on thetransmission of the ,motor truck. The tank 18 is mounted in anyconvenient manner on the chassis and supplies fluid, such as oil,through a conduit 21 to the pump 19, whence it is delivered under highpressure through a conduit 22 to the valve 10 which controls the supplyof oil to the jack through a connecting conduit 23. A conduit 24 extendsfrom the valve to the tank 18 for returning fluid thereto.

The valve 10 comprises a casting having inlet, supply and exhaust portsfor receiving the conduits 22, 23 and 24, respectively. A taperingtransverse bore through the casting accommodates a valve plug 25 whichis recessed so as to establish communication betweenA different valveports, when moved to different positions,` or to close certain ports. Areciprocating plug might be substituted, of course, for the rotary plugshown. 'Ihe valve plug bore is intersected by a plurality of passagesleading from the various ports. A passage 26 extends from the inlet portto the valve plug bore and accommodates a check valve A27. A shortpassage 28 extends directly from the valve plug bore to the supply portand the conduit 23. The exhaust port which receives j the conduit 24 isin communication with the valve plug bore through a main passage l29 andan auxiliary passage 30.

'I'he valve plug 25, as shown in Figure 4, is in the holding posit-ion.The passage=28 is'shut oi and any fluid Ainthe conduit 23 andthe hoist15, or otheruid-operated device controlled by the valve, is trappedtherein so that the device is held in,` operated position. When thevalve plug is in holding position, it will be observed that the passages26 and 29 are in communication through the lower valve plug recess sothat additional oil supplied to the valve isby-passed around thefluid-operated device and is returned directly to the tank 18 through,the exhaust conduit 24. In systems of the character described, it iscustomary to operateY the pump 19 continuously so as to have operatingpressure available at all times. As just explained, however, provisionis made for continual circulation of oil under low pressure even whenthe fluid-operated device is merely being held in completely orpartially operated position. By circulating oil continuously under lowpressure, the entire system is prevented from overheating and the loadon the pump is reduced to a minimum.

It will be obvious that turning the valve plug counterclockwise asviewed in Figure 4, establishes connection between the passages 26 and28, and at the same time closes the path through both` the passages 26and 29. When the valve plug is in this position, the oil is suppliedthrough the passage 28 of the `conduit 23 to the jack or other devicevfor further operation thereof. When the operation of the device hasbeen completed, the valve may be manually returned to the-Y illustratedposition. In order to prevent damage to the apparatus which might resultfrom failure to return the valve manually to the holding position shown,however, we provide automatic means for by-passing fluid supplied to thevalve after the jack has been fully extended. A check Valve 27 preventsescape of the uid in the jack and connecting conduits and passages eventhoughthe valve plug 25 remains in theV to the by-passing passage by themechanism,

aboutto be described. By turning the valve plug 25 in' the clockwisedirection as viewed in Figure v4, it is obvious thatipassages 28 and 30will be placed in communication, as well as passages 26 and 29. Theresult of this operation, of course, is to permit the fluid from thecylinder of the jack 15 to ow back to the tank 18 through the conduit 28while simultaneously permitting the free flow of additional oil from thepump through passages 26 and 29 to the tank. y

'Ihe automatic means for byfpassing oil after full operation of the jackor other device includes a by-passing valve 31 ofthe piston or sleevetype, and a relief valve. 'Ihe valve 31 is reciprocable in a cylinder 32bored in the valve casting, andA has its upper end open. It is providedwith lateral ports 33 adapted to register with an annular enlargement 34in the wall of the cylinder 32, which is in communication with the inletport into which the inlet conduit 22 extends. A resetting spring 35normally maintains the valve 31 in the illustrated position.v An exhaustpassage 36 extends from the upper end of the cylinder 32 and has alaterally extending portion 37 in communicationr with the passage 29.

Ihe relief valve indicated at 38 is subject to the pressure inthe supplyor inlet conduit 22 through a port 39 communicating with the annularenlargement 34 in the cylinder 32. "A spring 40 With the usual adjustingmeans normally seats the valve 38. A passage 41 extends from thechamberin which the valve `38 is located to the'lower end of thecylinder 32. A passage 42 extends from the relief valve chamber to thevalve plug bore. As shown in Figure 3a, the

valve plug 25 has an auxiliary/recess 25a in addition to the mainrecesses illustratedin 1 ?"igure4,`

Theauxiliary reces's is located 'so"that it will establish communicationbetween the passage 42 and the passage 29` when the valve plug is`actuated from the cab of the motor truck,ufor.

example, by'alinkABa and any suitable lhand lever. `The valve plug ismaintained in position in thebore by the adjusting means 44.

y The `operation ofthe single vvalve will now be described, assumingthat thevalvev plug is in` lowering position, namely, suchjthat thepassages 28Aand 30 are connected, and' likewise the pasa sages 26 and29. It will also be assumed that the l check valve 27 is openedsufliciently-to permit the ow of oilthrough the valve casting and thatthe by-pass and relief valves are in their illustrated positions. Aslong as such conditions exist and the pump 19 is driven, oil willcirculate through the valve, as before indicatedyhaving only thepressure of the spring behind the check valve 27 to overcome. Thispressure is preferably small so that the pump is practically idle underthese` conditions. Since fresh `oil is supplied to the pump from thetank continuously, there is no danger of overheating. i

When it is desired `to operate the-jack' 15 or other similar `devicecontrolled by the valve 10, the valve plug '25 is shiftedcounterclockwise so that the connection between the passages 26 and` 29`is broken `and the former Iisconnected to the passage 28. Oil is thussupplied under pressure tothe hoisting jack, which extends gradually.

kThe hoisting operation may be manually stopped at any point byreturning the valve Iplug to the holding -position illustrated in Figure4, or may be permitted to continue until it is completed.

When the hoist extension is completedthe presa sure of the fluid in theconduit 22 buildsup and is communicated through the enlargement 34 inthe cylinder 32 and the passage 39 to the`relief valve 38. `'I'he reliefvalve and its spring are dimensioned and adjusted so that the valve willnot operate under normal hoisting pressure. When the hoist extension 'iscompleted, the pressure will be increased above thenormal hoistingpressure and the same result will follow in case the load on the jack isgreater than normal. VIn either case, the fluid pressurewill open thevalve 38, whereupon oil iiows .throughtherelief valve chamber and thepassage 41 intothe bottom of the cylinder32. When the valve plug 25 isin the hoisting position, the passage 42 is closed at' its upper` end.The oil flowing into the cylinder 32 raises the piston valve 31 againstthe `force of the spring 35` until the ports 33 `in the valve pistonregisterwith the enlargement 34 in the cylinder 32.v This immediatelyrelievesfthe pressure 'in the conduit 22 since the oil may now flowthrough the enlargement34, the ports 33, the piston valve ing receives,'a piston a valve 72 recprocably a 31 and its openA upper end intothevpassage 36 and thence by the lateral extension 37 thereof,V

The oil` under thepiston `valve 31 is thereby trapped and the by-passingvalve is thereby maintained in its` upper position and permits"continued by-passing of oil around the main valve plug. These conditionspersist `until the sage55.

valve plug is restored to holding or lowering position. a

When it is desired to lower the jack, the valve plug is turned clockwisefrom the lraising position to; the holdingvposition illustratedin Figure4. This movement traps the oil in the jack cylinder but establishescommunication between the "passages 26 and 29. Similarly, the end of thepassage 42 is placed in communication with `the passage 29 and thespring 35 is free `to force thepiston 31 downwardly and eject the oilac- 'cumulated thereunder through the passage 42. The initially assumedconditions are thus restored except for the movement of the valve plug 25 to the lowering position topermit `theflow of-oil back throughthepassage 28 from the` jack tothe tank with the continuedby-passing ofoil from the inlet to the outlet conduit. y

Referring now to Figures 6' through 11, Isimilar principles have beenused in providing a valve which nmay be single or multiple, certainfeatures of which are also disclosed and claimed in a copendingapplication of Robert V. Proctor, et al., Serial N0, 583,862. a a

, The improved single cr multiple valve comprises a casting 50 having aplurality of tapered bores 51 for receiving valve Vplugs 52 which aresimilar in `general vto the valve plug 25, of the "single valve. Thecasting is also provided with inlet and outlet` ports 53 and 54 to whichsuit-` able supply and exhaust yconduits may be connected. HighTpressure and low pressure passages 55 and 56extend longitudinally ofthe casting and are in communication with the inlet and low pressurepassages tof/the bores. i Recesses 61 inthe upperzendof the valve plugs52 control the connection `of thepassages 59 and 60 to the supplypassages and ports 57 and `58. A check valve 62 is located in Asubstantially vertical passage 63 extends downwardly from the highpressure passage`55 to a `longitudinal by-passing passage 64. Aninclined passage 65 connects the end of the bypassing passage 64 to thelow pressurepassage 56; l `The )oy-passing `passage 64 is `controlled byrecesses 66 in the loweiJ portionsof the valve plugs` 52. The positionsofY the vrecesses 66 in thevarious plugs control the opening and closingof ports 67 through 70 associated with each` plug. When v"all the plugsarej normal position, as indicated infFigure 8, a continuous pathl forthe flow of oil is provided through the bypassing passage.v The oil inthe by-passing passage iiows through.` each of the valve plugs in seriesand afterpassing through `,all thewplugs,

A transverse' cylindrical bore 7l in the casttherein. `I'hisvalve haslateral ports 73 and 74 adapted respectively to register withannularenlargements` and 76 in the cylindrical bore- Va passage 78 withthe low pressurepassage 56 and outlet port 54. A spring 79 normallymainthe. high pressure `pas-` it enters the low pressure passage 56through the l y connecting passage 65. l

tains the piston valve in its illustrated posi-T tion. Aprojection 80from the closed end of the piston valve extends through '.i packinglgland 81 to permit mechanical operation of the valve.

A relief valve 82. similar to the valve 38 of the modification of thcinvention first described, is located in a. suitable chamber bored outof the casting 50.` A bore 83 ext-ends downwardly from the inlet port 53and communicates with the short passage 84 leading to the relief valve.From the relief valve chamber. a passage 85 extends to the cylindricalbore 7l for supplying oil thereto to operate the valve 72. A bleedervalve 86 connects the passage 85 with the by-passing passage`64.

In describing the operation of the multiple valve. it will be assumedthat eac-h ofthe valve pli "s is in one of the positions illustrated inFigure 8. When the lower portions of the valve plugs have the positionsthere shown. the upper portions are disposed as shown in Figure 9. Thisis the holding position in which the passages leading from the ports 57and 58 are closed so that any devices controlled by the valve plugs.which may have been operated are held in operated position.

When all the valve plugs are in holding position. oil supplied to thcvalve casting under pressure traverses the inlet port 53 and enters thehigh pressure passage by displacing the check valve 62. Because of theposition of the valve plugs, no oil can flow through the passages 59.There is a `continuouspath for the oil, however, through the passage 63leading to the by-passing passage 64. the inclined passage and the lowpressure passage 56. whence theol flows through the outlet 54 andreturns to the tank. as in the system of Figure 1. While the recesses lnthe lower portions of certain of the valve plugs may be reversed asshown in Figure 8, there is nevertheless a. continuous passage throughthe valve ports so that circulation of oil under low 'pressure ispermitted.

If it is desired to operate one of the devices controlled by the valveplugs. for example. that shown at the right of Figure 8. the valve plugis shifted counterclockwise until its upper and lower portions have thepositions shown in dotted lines in Figures 9 and 8. respectively. Thismovement of the valvey establishes connection between the passage 59 andthe port 58 associated with that particular valveplug. Oil underpressure I thus flows fromthe high pressure passage to thefluid-operated device. The lower portion of the valve closes the port 70in the by-passing passage associated therewith so that oil cannot flowthrough the by-pass but must flow toward the jack or other devicecontrolled by the valve plug in question. The operation of the devicecontinues until it reaches its limit of operation, whereupon thepressure in the supply line builds up sufliciently to displace therelief valve 82 which is in communication with the inlet 53 by the bore83. As before stated. the construct-ion and adjustment of the reliefvalve is such as to prevent opening thereof until abnormal pressures areapplied thereto, indicating the completion of the operation of thedevice or an abnormal load thereupon. The opening of the relief valve 82permits the oil to flow from the inlet through the passage into thecylinder 7l. The piston valve in the cylinder is thereby operated and`compressesV its spring 79 until the ports 73 and 74 are inregistry withthe enlargements 77 and 76, respectively. in the cylindrical bore 71. Onthe occurrence of this condition. the oil in the inlet 53 is by-passedthrough the passage 79, the

piston valve 72 and the passage 78 to the low' pressure passage 56 andthe outlet 54. The reduction of the pressure in the inlet following theby-passing permits the closing of the valve 82 to hold the by-pass valvein operated position. During the aforementioned operations, the bleedervalve 86 is maintained closed by the pressure in the by-passing passage64. This pressure, of course, is equal to the hoisting pressure. As longas the valve plug remains in the raising or .operating position. theweight of the load is sustained by the pressure on the oil in the highpressure passage 55and the by-passing passage 64 on the under side ofthe operated valve.

If the valve is now moved to the holding position as shown in Figures 8and 9, the by-passing passage is again opened up but the supply port 58is blocked of. The oil in the by-passing passage is thus relieved of thepressure exerted by the weight of the load. The bleeder valve 86 is thuspermitted to open to relieve the oil trapped in the cylinder 71. Thespring 79, of course, must be strong enough to operate the valve 86against the pressure of itsspring. During hoisting, the bleeder valve isurged to its closed position. as already stated,`and prevents thehoisting pressure from being effective tooperate the by-passing valve72. The normal by-passing passage having been re-established and therelief `to the dotted line position shown in Figures 8 and 9. The recessin the upper portion of the valveconnects the port 58 with the passage60 leading to the low pressure passage 56. oil trapped in the device isthus forced back to the tank. The clockwise movement of the valve,

The 4 plugdoes not cut off the normal by-passing passage since even inthe lowering position of the valve, the ports 69 and 70 in theby-passing passage are still in communication.

If it is desired, however, to use the valve plug forthe control of apair of double acting cylinders arranged so that when one is extendedthe other is retracted. this may be accomplished by reversing the valveplug in its bore, as shown to `the left inpFigure 8. valve when movedboth directions from such position is the same as that of the reversedplug except that turning the left-hand plug in Figure 8 in eitherdirection closes the normal by-passingl passage so that pressure isdeveloped in the high pressure passage 55 for operating another jack.`In the counterclockwise position, therefore, thek reversed valve plug atits upper portion would connect the port 57 with the passage 60 so as topermit reverse flow of the fluid therethrough to the tank whileconveying fluid under pressure through the port 58.- Conversely, whenthe valve is shifted clockwise, the port 58 is connected to the passage60 for retraction of the jack, for example, connected thereto, while theport 57 is connected to the high pressure passage 59 so that a jackconnected thereto would be extended.

In the several figures of the drawings. there are shown a number ofauxiliary bores and passages. some of which are closed by suitableplugs. These are necessarily formed in the machining of the casting butare not described specifically since it is thought their function willbe obvious from the drawings.

The valve shown in Figures 1 through 6 is The operation of the f chieflyintended for use to control jacks on reset .v forvalvesso mountedalthough it.is,"of

course, `feasible touse the pressure resetting `as well.yThemultiplegvalvefshown in Figures 6 through r11, however, is generallyto be preferred where a plurality of i jacks arerto be` controlledA forexample, the jacks for hoisting the bodieslof a truck and trailercombination :In such arrangel ment, it is sometimes desirable topermitmei chanical trippingiof the by-ip'assing valve and for l that reasontheprojectlon .onthe piston `valve,

72 `is provided.- iAnyf suitablefmechanical means may be employed toypush the projection. 80 inwardly `to operate the by-.pass valve-when.con-

ditions require the `oxtaerationthereof.` i

` It will be apparentfrom .the foregoingdescription that the inventionprovides fa valve having means for diverting oil from a fluid-operateddevice when the latter has reached fthe' limit oi' its `movementand`return the oil to the storage tank, vwithout restoringwtheoperatingfhan'dle or `lever` -of thevalve. 'Ihe `possibilityofi the`operators `hand beinginjured by sudden resettingofflthe valve lever isthusk obviatedn Other advantages are thefactthat, in aimultiple valve,the Vtime requireds for resetting is the same `whetherwone i or morevalves have been operated.l The multiple valve `is further advantageousbecause it .permits the concentrationoffthe control of a numberv ofdifferent devices within the reach of a single operator. Since theresetting takes place as soon as the first valve operated is restored toholding position, any number of other valves can then be operated beforeshifting the valveto the" lowering position. .As stated, the multiple`form ofthe valve `may have only a single'plug and thereby constituteactually a single valve.

Although we `have illustrated `and described herein but two embodimentsof our invention, it is obvious that numerous vchanges in the`constructiondescribed and illustrated may be made without departingfromthe spirit of the invention or the scope of the appended claims.

We claim: l h 1.. In a valve, a casing having inlet, supply and exhaustports and a plug controlling the connection of 'said ports, a by-passingvalve in said casing for connecting the inlet and exhaust ports, arelief valve subject to the pressure in the inlet port for causing` theoperation of the by-passing valve,` and means effective for causingithe`bypassing valve to close whenthe valve plug Yis shifted to connect theinlet and exhaust ports.

`2. A valve comprising a casing having inlet,1 supply and exhaust ports,a plug in `said casing for controlling the connection of said ports, anauxiliary valve in said casing for connecting the inlet and exhaustports, `a relief valve responsive to a predetermined pressure .in theinlet for ad-` mitting operating fluid to the auxiliary valve, saidrelief valve being effective after operation of the auxiliary valve toprevent resetting thereof, and a recess in said plug for releasing thefluid.

behind said auxiliary valvewhen the valve plug is moved to connect theinlet and exhaust ports.

3. A valve structure comprising a casing having inlet, supplyl and.exhaust ports, a valve plug for controlling, the'connection of saidports, a `spring-'closed piston valve for connecting theinlet andexhaust ports, a relief valvefor admitting` operatingfiuid'to'"the'piston valve upon the occurrence of `a-predetermined fluid pressure `inthe inlet portfsaid` relief `valve having means for reseating itfon` thedrop in pressure intheinlet resulting yfrom the operation of fthe pistonvalve,`

and'. meansfcontrolledby thefmovement of the valve plug for releasingthefluid behind the pistonlvalve to permit closing Vof the latterunder theinfluence ofiits spring. Y

V4. In a 'valve structure, erasing, inlet, supply h andexhaustports'tinthe\casing,la valvev plug therein for lcontrolling theV connection ofysaid ports.. a lay-passingr valve "for" connecting said `inletandexhaust ports, said by-pas'sing' valve comprising apistonreciprocablein` a-cylindrical bore l in thexcasinga relief "valve'foradmittingoper- `ating fluid to said piston upon the occurrence of vapredetermined pressure'in-said inlet, said `re liefvalve-havingmeans-forreseating it upon -the by the-latter is heldin'operated position, means responsiveto th'e rotation of f the valve'plugi for `releasing `the fluid behind-thepistonivalve, and

i drop in i pressure in Ithe inlet resulting" from the operation of 'thepiston; by-passing valve wheremeans for restoring'the lattertoitsvin'itial yposii tion. i

5. In a multiple valve, `a casing-havingl inlet and exhaust ports, aplurality of3valve 'plugs rotatablevin bores :in said casing,highpressure and low pressure passages communicating with said inletand' exhaust vportsv and said valve`=plug-bo`res, a iby-passing:Gpas'sage lextending from said high pressure passage to `said low'p'r'essiue` passage through saidbor'es, each -ofv said valve plugs hav-Sage.

6. In a valve, a casing having inlet and exhaust ports, a valve plugseated in a `bore in said cas-V ing, supply ports adapted to beg placedincommunication with said inlet and exhaustiports by said valve plug, aby-passing passage extending l from the inlet to the-exhaust port andclosed by 1 supply and exhaust ports, and a valve plug for controllingthe connection of said ports, a bypassing passage,` said plug havingmeans for closing said passage, a check valve between the inlet and thevalve plug, a piston type by-passing valve reciprocable` in saidcasinggand means for supplying operating fluid thereto only upon theoccurrence of a predetermined pressure in said inlet.

`8. In a multiple valve, a casing, inlet and exingportions ladapted toclose 'said `by-passing pa'si haust ports in said casing, high pressureand low pressurepassages extending `from said ports,`sup

` ply ports in said casing.; and valve plugs rotatably a predeterminedpressure in the inlet, and trapping said fluid behind the piston uponthe drop in inlet Ypressure resulting from the operation of theby-passing valve, a passage connectingthe `by-passing valve piston uponthe occurrence of piston chamber withY the by-passing passage, a

bleeder check valve in said passage for prevent- -ing operation of` theby-passing` valve by the pressure inthe by-passing passage, and meansfor resetting the by-passing valve, said means bes piston exhaust portsin theA casing, a normally open byl passing passage connecting saidinlet and exvsupply ports.

haust ports, said passage extending through each ofy said plugs, highpressure and low pressure passages extending from said inlet and exhaustports for connection to said supply ports on rotation of said plugs,saidplugs being effective to close said by-passing passagewhen rotatedin at least one direction,.for building up pressure in one of said11.`In a valve, a casing,` inlet and exhaust ports in thev casing, alay-passing passage connecting said inlet and exhaust ports, a checkvalve between the inlet and the'jpassage, a lay-passing pistonvalve,vpressure responsive meansvfor operating said piston valve, apassage connecting the piston'` chamber with the lay-passing passage, acheck valve normally closing-said last-mentioned rits valve. Y y

12.k In a valve structure, a casing having inlet,

.the by-passing valve.

passage to prevent premature operation of said .by-passing valvebyforcing the fluid behind the piston through saidlast-mentioned passageand supply and exhaust ports, valve plugsrotatable `in the casing forconnecting said ports, a by-pass passage through said casingcontrolledby each of said valves, a by-passing `piston valve,pressureresponsive means for causing actuation of the piston valve, andmeans responsive to the movement of .one of said plugs toa position suchthat it cuts off-itssupply portsfromthe inlet port, for resetting the`piston valve.

13. In a multiple valve, inlet, supplyzand exhaust ports, identicalvalve vplugs ..1otatable in bores in said casing` for controlling theconnection of said ports, certain'of said-plugs control.

ling a single hydraulic device and other plugs controlling a pluralityof devices, the plugs controlling a single device being disposed intheir bores reversely tothe ,plugs controlling a plurality of devices. il

i4. A multiple valve comprising a casing, a plurality of valve plugsrotatable therein, inlet, supply and exhaust vports in the casingconnectible to veach-other throughzsaid plugs, a by-pa-ssing passage`connecting* the inlet and vexhaustports, said passage being "closedbyoperation of any one ofsaid plugs,V azsecond'by-passing passage, aby-passing valve therein, and means responsive to the pressure in theinlet for operating ROBERT Vl PROCTGR.' WILLIAM T. STEPHENS.

